From ab2fded8affbaf93dfd2c086cb473706070db16b Mon Sep 17 00:00:00 2001
From: Joose Sainio <joose.sainio@tut.fi>
Date: Thu, 21 Nov 2019 13:38:40 +0200
Subject: [PATCH] Update threadwrapper to enable pthread_rwlock_t

---
 src/threadwrapper/include/pthread.h |  8 +++++
 src/threadwrapper/src/pthread.cpp   | 45 +++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/src/threadwrapper/include/pthread.h b/src/threadwrapper/include/pthread.h
index eeef31d5..a6a04d8e 100644
--- a/src/threadwrapper/include/pthread.h
+++ b/src/threadwrapper/include/pthread.h
@@ -23,12 +23,14 @@ extern "C" {
 typedef void* pthread_cond_t;
 typedef void* pthread_cond_t;
 typedef void* pthread_mutex_t;
+typedef void* pthread_rwlock_t;
 typedef void* pthread_t;
 typedef void*(voidp_voidp_func)(void*);
 
 typedef void pthread_attr_t;
 typedef void pthread_condattr_t;
 typedef void pthread_mutexattr_t;
+typedef void pthread_rwlockattr_t;
 
 // Parameter names that have been commented away do nothing,
 // as they are always null when the functions are used in Kvazaar.
@@ -48,6 +50,12 @@ int pthread_mutex_init(pthread_mutex_t* mutex, const pthread_mutexattr_t* /*attr
 int pthread_mutex_lock(pthread_mutex_t* mutex);
 int pthread_mutex_unlock(pthread_mutex_t* mutex);
 
+int pthread_rwlock_init(pthread_rwlock_t* lock, const pthread_rwlockattr_t * /*attr*/);
+int pthread_rwlock_destroy(pthread_rwlock_t *rwlock);
+int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock);
+int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);
+int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/threadwrapper/src/pthread.cpp b/src/threadwrapper/src/pthread.cpp
index 7e094b9e..56e92f3d 100644
--- a/src/threadwrapper/src/pthread.cpp
+++ b/src/threadwrapper/src/pthread.cpp
@@ -17,8 +17,13 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "pthread.h"
 #include <condition_variable>
 #include <mutex>
+#include <shared_mutex>
 #include <thread>
 
+typedef struct {
+  std::shared_mutex *lock;
+  bool write_lock;
+} rw_lock_internal;
 
 int pthread_cond_broadcast(pthread_cond_t* cond) {
     static_cast<std::condition_variable*>(*cond)->notify_all();
@@ -86,3 +91,43 @@ int pthread_mutex_unlock(pthread_mutex_t* mutex) {
     static_cast<std::mutex*>(*mutex)->unlock();
     return 0;
 }
+
+int pthread_rwlock_init(pthread_rwlock_t * lock, const pthread_rwlockattr_t *)
+{
+  *lock = new rw_lock_internal;
+  static_cast<rw_lock_internal*>(*lock)->lock = new std::shared_mutex;
+  static_cast<rw_lock_internal*>(*lock)->write_lock = false;
+  return 0;
+}
+
+int pthread_rwlock_destroy(pthread_rwlock_t* rwlock)
+{
+  delete static_cast<rw_lock_internal*>(*rwlock)->lock;
+  delete static_cast<rw_lock_internal*>(*rwlock);
+  return 0;
+}
+
+int pthread_rwlock_rdlock(pthread_rwlock_t* rwlock)
+{
+  static_cast<rw_lock_internal*>(*rwlock)->lock->lock_shared();
+  return 0;
+}
+
+int pthread_rwlock_wrlock(pthread_rwlock_t* rwlock)
+{
+  static_cast<rw_lock_internal*>(*rwlock)->lock->lock();
+  static_cast<rw_lock_internal*>(*rwlock)->write_lock = true;
+  return 0;
+}
+
+int pthread_rwlock_unlock(pthread_rwlock_t* rwlock)
+{
+  if (static_cast<rw_lock_internal*>(*rwlock)->write_lock) {
+    static_cast<rw_lock_internal*>(*rwlock)->write_lock = false;
+    static_cast<rw_lock_internal*>(*rwlock)->lock->unlock();
+  }
+  else {
+    static_cast<rw_lock_internal*>(*rwlock)->lock->unlock_shared();
+  }
+  return 0;
+}